José Manuel Ruiz Román

• Doctor of Engineering
• Catedrático de Universidad at Universidad Politécnica de Madrid

Metal matrix syntactic foams (MMSF) are advanced cellular materials constituted by a system of a minimum of two phases, in which a dispersion of hollow particles is embedded by a continuous metal matrix. The incorporation of porous fillers favors the development of low-density materials with exceptional behavior for damping vibrations, impacts, and...

Metal matrix syntactic foams (MMSFs) are advanced lightweight materials constituted by a metallic matrix and a dispersion of hollow/porous fillers. Physical and mechanical properties can be fitted regarding matrix and filler properties and processing parameters. Their properties make them potential materials for sectors where density is a limiting...

n the present investigation, an experimental design of hybrid structures based on advanced poremorphology (APM) Al foam spheroid elements is studied. The energy absorption capacities of three configura-tions is assessed for both quasi-static and dynamic compressive loads. To this end experimental tests were per-formed by means of a universal testin...

Metal matrix syntactic foams (MMSF) are foam composites obtained by filling hollow and/or porous particles into a metal matrix. MMSF are promising materials in defense, aerospace, automotive, marine and engineering applications. Mechanical and physical properties of MMSF can be tailored to reach better structural and/or functional behaviors by fitt...

Functionally Graded Mo sintered steels. Functionally graded materials (FGM), the multi-materials, strive to satisfy the numerous requirements demanded of parts in a given combination of compositions and microstructures. The required material compatibility lead the manufacturing process and the achieving of an interface, not always diffuse. Powder m...

Concentrated solar energy was applied to welded foam plates in non-protective atmosphere. The filler was a pore-generating aluminium–silicon alloy placed between two commercial aluminium foam plates. The heating device provided enough energy to melt and foam the filler. The heat affected surfaces on foam plates and welding mechanisms were correlate...

El presente trabajo plantea la reutilización directa de escorias de aluminio procedentes de la metalurgia secundaria mediante. La escoria con un contenido variable del 10-20% de aluminio metálico y oxido de aluminio es triturada hasta obtener una fracción inferior a las 600 micras. Las mezclas con arcilla en contenidos del 10 y 20% de escoria se re...

La aplicación de la energía solar concentrada en la fabricación de espumas de aluminio de poro cerrado obtenido mediante técnicas pulvimetalúrgias permite el calentamiento del material (precursor) hasta su fusión y la formación de la espuma. En el presente trabajo, precursores Al10Si+0.8%TiH2, se han sometido al tratamiento de espumación en el horn...

The objective of the present work is the recovery of slate wastes into a raw material for the ceramic industry. Foams are obtained without any addition of foaming agent thanks to the transformation of component present on the slate during heating. A glass base material with a closed porosity, gray color and density value around to 0,3g/cm3 has been...

Commercial aluminum foam filled structures and sandwich panels are available for structural applications. As alternative to these materials, small granular foamed pieces are proposed to fill structures as well as sandwich panels. On the present work, foam precursors are obtained by Powder Metallurgy (PM) route, using natural calcium carbonate as fo...

The purpose of this work was to study the feasibility of aluminum foaming using concentrated solar energy. To this end, we used concentrated solar energy directly on parts (foam precursors) and to generate process heat. As a consequence, a foaming agent is thermal decomposed into an aluminum melt, leading to obtain aluminium foam. Due to that, manu...

En este trabajo se analizan las propiedades de tres hierros aleados sintetizados y tratados al vapor. Los materiales seleccionados son el Fe+2Cu, Fe+0.6C+0.5Cu, y Fe+0.45P+2.5Cu, obtenidos por mezcla elemental de polvos. Una vez compactados y sintetizados, se sometieron a un tratamiento de recubrimiento caracteristico de los hierros, como es el tra...

In the present work we have studied the feasibility of Powder Metallurgy in order to obtain structural ceramics from residual fly ashes powders. Characterization of powders has been carried out followed with the manufacturion of a structural ceramic through poeder compacting and sintering. Some physical and mechanical properties as density, dimensi...

En este trabajo se estudia la eficacia del empleo de la aleacion mecanica, en el proceso de fabricacion de materiales compuestos de matriz metalica (base acero rapido M2) mediante tecnicas pulvimetalurgicas. Del analisis de los materiales obtenidos, acero rapido M2 reforzado con WC, se deduce que la aleacion mecanica resulta ser un metodo eficaz pa...

The decomposition of constituents of slates under non-oxidizing atmosphere leads to the manufacturing of foams. Thus die pressing at 80MPa of slates powders (particle size <80 microns) mixed with a solid agglomerate, allows a green density close to 1,8 g/cm3 . The heating of compacts under N2-5%H2 atmosphere allows to reach a final density of 2,2 g...

On the present work the objective is to manufacture a AA2014+10 vol-% Intermetallic (NbAl3 or FeAl2 ) metal matrix composites. Since Powder Metallurgy route was chosen, the powder mixtures of metallic powders which forms AA2014 alloy and intermetallic powders were obtained by mechanical alloying. Powder mixtures were cold die pressing and green sam...

Aluminium is added to decrease matrix chromium losses on 430 stainless steel sintered on nitrogen atmosphere. Three different ways were used to add a 3% (in weight) aluminium: as elemental powder, as prealloyed powder, and as intermetallic Fe-Al compound. After die pressing at densities between 6. 1-6. 5 g/cm3, samples were sintered on vacuum and o...

Solar energy is used for the work reported here as a nonconventional heating system to produce aluminium foam from AlSi alloy precursors produced by powder metallurgy. A commercial precursor in cylindrical bars enclosed in a stainless-steel mould was heated under concentrated solar radiation in a solar furnace with varied heating conditions (heatin...

Aluminium foams can be manufactured by two main methods: casting and powder metallurgy. When the latter route is used, a foaming agent (usually TiH2) is mixed with the aluminium or aluminium alloy powders, followed by powder mixture consolidation (usually hot extrusion) into a precursor and finally its foaming treatment. In this research, two calci...

Exposure methods (ASTM A262 Practice A and Modified Strauss Test) and electrochemical reactivation methods such as EPR and EPRDL was applied to PM 304L and PM 316L stainless and comparisons with wrought stainless steels were made. Sintering in vacuum and nitrogen–hydrogen atmosphere was chosen. The latter was the focus of the work and the former wa...

La fabricación de espumas de aluminio de poro cerrado mediante técnicas pulvimetalúrgias, conlleva una etapa de calentamiento del material (precursor) hasta su fusión y la formación de la espuma. En el presente trabajo, como continuación de los trabajos con energía solar concentrada aplicada directamente a la espumación de precursores Al10Si+0.8%Ti...

Die pressing parts needs lubricant admixed with base powders. Usually, lubricant elimination is carried out at the beginning of sintering on continuous belt furnaces. However on some PM parts lubricant burning is carried out before. This step can be carried out using concentrated solar energy, and thus take in advantages of this source of energy. T...

The decomposition of constituents of slates under non-oxidizing atmosphere leads to the manufacturing of foams. Thus die pressing at 80MPA of slates powders (particle size <80 microns) mixed with a solid agglomerate, allows a green density close to 1,8 g/cm3. The heating of compacts under N2-5%H2 atmosphere allows to reach a final density of 2,2 g/...

Die pressing parts need lubricant mixed with base powders. Usually, this lubricant is burned at the entrance of the continuous belt furnaces before sintering step. However on some PM parts, lubricant is burning before sintering on a separate furnace. This presintering treatment can be carried out using concentrated solar energy, and thus take in ad...

This article analyses the viability of Calcium Carbonate as a potential replacement of Titanium Hydride in the manufacturing of aluminum foams. Powder Metallurgy technique was carried on the production of Al12Si alloy foams with 10% wt. of milled white marble instead of 1% wt. of titanium hydride as foaming agent. The manufacturing process begins w...

La aplicación de la energía solar concentrada a precursores comerciales permite obtener espumas en molde cerrado. El presente trabajo analiza la aplicación directa de esta radiación a precursores de Al-7Si, con mármol como agente espumante, de menor conductividad que los precursores comerciales. La obtención de estos precursores se realiza a partir...

When high temperature is involved on bearings, graphite addition is added to keep good sliding properties. However, graphite decreases the bearing strength and reduce the sinterability of Bronze compacts. Nickel can increase the bronze resistance when Graphite is added, but Nickel powders have a strong tendency to segregation during mixing. A solut...

Several aluminum alloys have been reinforced successfully with ceramics particles. After mechanical alloying of a powder mixture of aluminum and reinforcement, hot extrusion give a sintered material with low porosity. Besides hardness or wear resistance, other properties can be improved with these ceramic additions. The present work shows the resul...

In this work, we put forward the use of the marble residues, as the extraction process residues as the manufacture ones, through the material compound from a determinated marble granulation over a polymer matrix.With this propose, we have several epoxidic, acrylic resins and specific products of different manufacturers. These materials have been di...

Low ductility, flexural resistance and impact resistance is a characteristic of cement mortars and concrete. This limits the application of these ceramics materials when dynamic loads are present. Then, fiber addition is one way to increase these properties, especially ductility.In this work, natural fibers from a plant known as “fique” are used as...

In this Work the influence of sintering AISI 430L stainless steel in N2-H2 atmosphere on its properties and microstructure have been studied. The presence of nitrogen in the sintering atmosphere leads to complex nitrides formation the AISI 430L sintered steel microstructure. A subsequent heat treatment was applied to modify this microstructure in o...

The objective of the present work is the recovery of slate wastes into a raw material for the ceramic industry. Foams are obtained without any addition of foaming agent thanks to the transformation of component present on the slate during heating. A glass base material with a closed porosity, gray color and density value around to 0,3g/cm3 has been...

In this paper, we have studied the nitrogen effects different sintering atmospheres (nitrogen-hydrogen, and dissociate ammonia) on ferritic stainless steels (430L), fabricated by powder metallurgy process. We have carried out a study of the physical (density, porosity and dimensional variation) and mechanical properties (hardness, tensile strength,...

In this paper, we have studied the nitrogen effects different sintering atmospheres (nitrogen-hydrogen, and dissociate ammonia) on ferritic stainless steels (430L), fabricated by powder metallurgy process. We have carried out a study of the physical (density, porosity and dimensional variation) and mechanical properties (hardness, tensile strength,...

The objective of the present work is the iron swarfs reusing as raw material to manufacture sintered parts. Particle size reduction using Horizontal attrition milling within iron dilution is the way used to get the raw materials. Two powder mixtures were obtained: Commercial Iron+50 % milled swarfs, and the milling mixture of iron+50 %swarfs. After...

The objective of the present work is the iron swarfs reusing as raw material to manufacture sintered parts. Particle size reduction using Horizontal attrition milling within iron dilution is the way used to get the raw materials. Two powder mixtures were obtained: Commercial Iron+50 % milled swarfs, and the milling mixture of iron+50 %swarfs. After...

In this Work the influence of sintering AISI 430L stainless steel in N 2-H 2 atmosphere on its properties and microstructure have been studied. The presence of nitrogen in the sintering atmosphere leads to complex nitrides formation the AISI 430L sintered steel microstructure. A subsequent heat treatment was applied to modify this microstructure in...

Foaming of Aluminium precursor (obtained by the Powder Metallurgy route) using a non conventional heating system (such as solar energy furnace) is the object of the present work. Thus, commercial Al-Si precursor bars were heated on solar energy furnace under several heating conditions (heating rate, time,…). Density, pore shape and distribution wer...

Manufacturing and characterization of bearing materials is the object of the present work. Thus, graphite particles are added to an aluminium matrix as lubricant. It was added as nickel coated graphite in order to avoid a strength decreasing. Mixing of powders following by cold compaction and hot extrusion was the manufacturing way. Extruded materi...

Manufacturing and characterization of bearing materials is the object of the present work. Thus, graphite particles are added to an aluminium matrix as lubricant. It was added as nickel coated graphite in order to avoid a strength decreasing. Mixing of powders following by cold compaction and hot extrusion was the manufacturing way. Extruded materi...

On the present work the objective is to manufacture a AA2014+10 vol-% Intermetallic (NbAl3 or FeAl2) metal matrix composites. Since Powder Metallurgy route was chosen, the powder mixtures of metallic powders which forms AA2014 alloy and intermetallic powders were obtained bv mechanical alloying. Powder mixtures were cold die pressing and green samp...

Manufacturing of metal matrix composites (MMCs) through powder metallurgy route and their characterisation are the objects of the present work. Thus a light alloy reinforced with 5% of ceramics is obtained after attrition milling of mixed powders, die pressing, lubrication of compacts and hot extrusion into 10 mm diameter bars. Since 7xxx series of...

Powder Metallurgy route was used to achieve a dispersion of 5% to 30% copper phosphorus particles (Cu-P) into the aluminium matrix. Thus, several aluminium-copper phosphorus Cu-P powder mixtures were obtained by mixing on a planetary mill. Die pressing and hot extrusion of these powder mixtures is the manufacturing way to achieve bars of 5mm of dia...

In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. Fr...

In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. Fr...

In the present work we have studied the feasibility of Powder Metallurgy in order to obtain structural ceramics from residual fly ashes powders. Characterization of powders has been carried out followed with the manufacturion of a structural ceramic through poeder compacting and sintering. Some physical and mechanical properties as density, dimensi...

En este trabajo se estudia la eficacia del empleo de la aleación mecánica, en el proceso de fabricación de materiales compuestos de matriz metálica (base acero rápido M2) mediante técnicas pulvimetalúrgicas. Del análisis de los materiales obtenidos, acero rápido M2 reforzado con WC, se deduce que la aleación mecánica resulta ser un método eficaz pa...

En el presente trabajo se ha investigado la posible utilización de un residuo de las centrales térmicas de carbón de hulla, como son las cenizas volantes silicoaluminosas (clase F) ocasionadas en los procesos de combustión, como materia prima para la fabricación de materiales cerámicos estructurales.De este modo se ha procedido a la caracterización...

In this work we compare an AISI M2 high speed steel obtained through conventional P/M technique with another obtained by metal injection moulding (MIM). MIM technology have been developed strongly during last ten years, thanks to it feasibility of making parts of high precision, complicate shape and low cost.

The purpose of this work is to study the feasibility of Powder Injection Molding in order to obtain M2 High Speed Steels with higher performances than those obtained by conventional P/M. With this object trials have been carried out in order to optimize all the process steps (mixing, injection, debinding and sintering), and to evaluate the mechanic...

The purpose of this work is to study the feasibility of Powder Injection Molding in order to obtain M2 High Speed Steels with higher performances than those obtained by conventional P/M. With this object trials have been carried out in order to optimize all the process steps (mixing, injection, debinding and sintering), and to evaluate the mechanic...

In the present work Portland clinker is used as a matrix of a composite material which uses Al2O3 and SiC as reinforcements. The manufacturing process of this material includes mixing, cold isostatic pressing and sintering. The sinterability of composite materials was evaluated. Mechanical properties, microstructure and mechanical reliability - usi...

Types 316L (UNS S31603) and 304L (UNS S30403) sintered stainless steels (SS) were produced in a laboratory furnace at 1,330°C and infiltrated with copper and bronze in different percentages to determine their effect on the corrosion resistance of the presintered SS. Corrosion resistance was studied by immersion in sulfuric (H2SO4), hydrochloric (HC...

Corrosion behaviour of different P/M stainless steels have been studied through immersion and potenciodinamic tests. The studied materials were two austenitic and ferritic grades, and different duplex steels obtained both from prealloyed powders, and through mixing ferritic and austenitic powders at different percentages.

Sintered molybdenum-, copper-, nickel- alloyed steels, have been studied through the influence of the Chemical composition on different mechanical and physical properties. In all the studied steels, a constant percentage of carbon has been used, as well Fe-Mo prealloyed powders, with a 1,5% Mo content. Selected sintering conditions were close to th...

The feasibility of cast iron swarf utilization as a raw material in the powder metallurgy industry has been studied. This work derives the possibility of making steel components from cast iron swarf powder with P/M techniques. Cast iron swarfs have been used as a direct additive in the manufacturing of steels, without making any other preliminary p...

RESUMEN La viabilidad de emplear materiales de carácter puzolánico como materiales para la construcción, en particular como adición en morteros de cemento, es el objeto de presente estudio. Así materiales volcánicos de carácter ácido procedente de la Republica de El Salvador son analizados siguiendo la normativa española. Con el uso de tales materi...